GRG 301C Lecture Notes - Lecture 3: Sea Level Rise, Dengue Fever, Angle Of Rotation
Document Summary
Basic: climate change = global problem with grave environmental, social, economic, political implications, science is clear that climate change is real and that it is happening now, effects: Pope addressed it and agreed it was something we needed to worry about. Climate conditions are exceeding the bounds of natural variability. Models estimate that without human influences, average atmospheric temperatures would"ve decreased over last few decades. The climate system: not just the atmosphere. Natural forcings of climate change: plate tectonics. Land masses move closer/farther equator and poles. Repositioning of land masses changes not only isolation but also alters atmospheric and oceanic currents: variations in earth"s orbit and rotation angle. Known as millankovitch cycles; long term (10 of thousands of years) Changes in axial angle of the earth relative to the sun. Variations in the shape of the earth"s orbit (eccentricity: volcanic activity. Shoots ash into the atmosphere (aerosols blocking sunlight cooling) Gas emissions (some of which are greenhouse gases warming)